AP BIOLOGY

Detailed explanation-1: -If that’s the case, Earth’s first life (or at least the first life that left descendants) would have resembled the microbes that cluster around deep-sea vents today, the researchers said.

Detailed explanation-2: -The earliest life forms we know of were microscopic organisms (microbes) that left signals of their presence in rocks about 3.7 billion years old.

Detailed explanation-3: -They were the only life forms until about 2.1 billion years ago. Other life forms evolved from bacteria. Bacteria grow, reproduce, and carry out respiration.

Detailed explanation-4: -Some of the oldest evidence of life on Earth is 3.49-billion-year-old fossilised remains of microbial mat structures, which look like wrinkle marks in rocks, found in the Pilbara region of Western Australia.